EP2662668B1 - Échelle, codeur vernier et appareil l'utilisant - Google Patents

Échelle, codeur vernier et appareil l'utilisant Download PDF

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Publication number
EP2662668B1
EP2662668B1 EP13166364.3A EP13166364A EP2662668B1 EP 2662668 B1 EP2662668 B1 EP 2662668B1 EP 13166364 A EP13166364 A EP 13166364A EP 2662668 B1 EP2662668 B1 EP 2662668B1
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Prior art keywords
scale
period
periodic
periodic pattern
track
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German (de)
English (en)
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EP2662668A2 (fr
EP2662668A3 (fr
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Haruhiko Horiguchi
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Canon Inc
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Canon Inc
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
    • G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
    • G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
    • G01D5/347—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells using displacement encoding scales
    • G01D5/34707—Scales; Discs, e.g. fixation, fabrication, compensation
    • G01D5/34715—Scale reading or illumination devices
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
    • G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
    • G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
    • G01D5/347—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells using displacement encoding scales

Definitions

  • the present invention basically relates to a scale and an encoder to be used for detecting position (or movement/rotation amount) of a movable member by using a vernier method.
  • Encoders to be used for position detection include optical encoder and magnetic encoders, both of which are constituted by a sensor to be attached to one of a movable member and a fixed (immovable) member and a scale to be attached to the other of the sensor and the scale.
  • the scale is provided with a periodic pattern periodically transmitting or reflecting light or periodically changing intensity of magnetic field.
  • the sensor optically or magnetically reads the periodic pattern in the scale to produce an electric signal (sensor output signal) corresponding to the periodic pattern. Calculation using this sensor output signal enables detection of position (or movement/rotation amount) of the movable member.
  • Japanese Patent Laid-Open No. 2011-033464 discloses an encoder including a scale that is provided with multiple (two) periodic patterns arranged parallel and having a phase difference therebetween.
  • a sensor including two light receivers reads these two periodic patterns to produce two sensor output signals having a phase difference therebetween. Performing calculation using the sensor output signals enables position detection with higher resolution.
  • the inventor of the present invention researches a vernier encoder, such as one shown in FIG. 12 , which uses a scale provided with two scale tracks 1008 and 1011.
  • Each of the scale tracks 1008 and 1011 includes multiple periodic patterns arranged parallel and having mutually different periods.
  • the scale track 1008 alternately includes periodic patterns (each hereinafter referred to as "a coarse pattern") 1111, 1121 and 1131 having long periods and periodic patterns (each hereinafter referred to as "a fine pattern") 1112, 1122 and 1132 having short periods.
  • the scale track 1011 alternately includes coarse patterns 1211, 1221 and 1231 and fine patterns 1212, 1222 and 1232.
  • the coarse patterns forming a pair between the two scale tracks have slightly different periods from each other, and the fine patterns forming a pair between the two scale tracks also have slightly different periods from each other.
  • a sensor of this encoder reads the paired coarse patterns to provide two sensor output signals having long periods slightly different from each other. Then, the encoder performs vernier operation to calculate a phase difference between the two sensor output signals and produces therefrom a vernier periodic signal having a long period different from those of the two sensor output signals. Similarly, the encoder reads the paired fine patterns to provide two sensor output signals having short periods slightly different from each other. Then, the encoder performs the vernier operation to calculate a phase difference between the two sensor output signals and produces therefrom another vernier periodic signal having a short period different from those of the two sensor output signals.
  • the encoder uses the long period vernier periodic signal thus obtained as a high-level signal Sv1 and uses the short period vernier periodic signal as a middle-level signal Sv2, and synchronizes the high-level signal Sv1 and the middle-level signal Sv2 to enable position detection.
  • the movable member and the fixed member to which the sensor and the scale are attached often have mechanical backlash therebetween in a scale width direction (Y direction in FIG. 12 ) orthogonal to a position detection direction (X direction in FIG. 12 ) that is a direction in which each periodic pattern extends.
  • the mechanical backlash causes a relative positional shift between the sensor and the scale in the scale width direction, which causes socalled cross talk in which the sensor reads the periodic pattern in the scale track different from the scale track that the sensor should read.
  • the cross talk results in a position detection error as shown in FIG. 13 .
  • FIG. 13 is a graph showing dependence of synchronization accuracy of the high- and middle-level signals Sv1 and Sv2 and dependence of position detection accuracy on relative positional shift amount between the sensor and the scale in the Y direction.
  • a solid line shows the synchronization accuracy of the high- and middle-level signals Sv1 and Sv2, and a broken line shows the position detection accuracy.
  • a horizontal axis shows the relative positional shift amount between the sensor and the scale in the Y direction.
  • the relative positional shift amount between the sensor and the scale in a +Y direction in FIG. 13 corresponds to a positional shift amount of the sensor with respect to the scale in an upper direction in FIG. 12
  • the relative positional shift amount between the sensor and the scale in a -Y direction in FIG. 13 corresponds to a positional shift amount of the sensor with respect to the scale in a lower direction in FIG. 12
  • a first vertical axis on a left side in the graph shows the synchronization accuracy between the high- and middle-level signals Sv1 and Sv2.
  • a synchronization accuracy exceeding 1 makes the synchronization between the high- and middle-level signals Sv1 and Sv2 impossible.
  • a second vertical axis on a right side in the graph shows the position detection accuracy.
  • Y1 represents a distance between a light emitter and a light receiver of the sensor in the scale width direction (see FIG. 1B ).
  • a sensor reading area where the sensor can read the periodic pattern includes a boundary 1031 between the two scale tracks, which causes the sensor to perform cross talk reading of the long period pattern (for example, the periodic pattern 1112) and the short periodic pattern (for example, the periodic pattern 1212) respectively included in the mutually different scale tracks.
  • increase of the relative positional shift amount of the sensor and scale makes the cross talk significant.
  • increase of the relative positional shift amount in the +Y direction increases influence of the cross talk on the high-level signal Sv1, which results in deterioration of accuracy of the high-level signal Sv1 and also results in the synchronization accuracy between the high- and middle-level signals Sv1 and Sv2.
  • the deterioration of the synchronization accuracy causes an error corresponding to at least one period in the middle-level signal Sv2, which significantly deteriorates the position detection accuracy as in the case where the relative positional shift amount is +Y1/2.
  • the document US 3 768 094 A discloses a digital encoder and a position reference. Specifically, there is described a position indicating apparatus having fixed and movable parts with one of the parts having magnetic position reference information thereon and the other part containing a flux sensitive element for sensing the position reference information and indicating the position of the sensor relative to the reference.
  • the reference may be linear, circular, or cylindrical to conform to the need for measuring linear and/or angular displacements.
  • the document US 2011/0049341 A1 discloses an optical encoder capable of improving the precision of an interpolation angle in a single signal track, in an encoder of sine-wave angle interpolation type.
  • the optical encoder includes a waveform, in which a phase-modulated wave is superimposed in a predetermined period over a sine-wave of a fundamental period, as a signal track, and an optical detector for extracting the sine signal and the cosine signal of the phase-modulated wave.
  • An operation unit operates electric angles individually from the output signals of a first optical detector pair and a second optical detector pair belonging to the optical detector, and determines the sum and difference of the electric angles, thereby acquiring the electric angle and the phase-modulated wave of the fundamental period.
  • the present invention provides a scale to be used for a vernier encoder, which includes a multiple track scale and is capable of increasing an allowable relative movement amount between the multiple track scale and a sensor in a scale width direction, without increasing in size of the sensor or the entire encoder. Moreover, the present invention provides a vernier encoder using such a scale and provides an apparatus using such a vernier encoder.
  • the present invention in its first aspect provides a scale as specified in claims 1 to 5.
  • the present invention in its second aspect provides a vernier encoder as specified in claims 6 and 7.
  • the present invention in its third aspect provides an apparatus as specified in claim 8.
  • FIGS. 1A and 1B show a configuration of a vernier encoder that is a first embodiment (Embodiment 1) of the present invention.
  • the encoder is constituted by a sensor unit 7 and a scale 2.
  • the sensor unit 7 is attached to a fixed member that is a member fixed to an immovable member such as a chassis of an apparatus (not shown) or a member fixed to the chassis.
  • the scale 2 is attached to a movable member 10 as a position detection object member that is linearly movable or rotatable with respect to the fixed member.
  • the encoder also includes a signal processor 51 and a memory 52.
  • a configuration may be employed in which the sensor unit 7 is attached to the movable member and the scale 2 is attached to the fixed member. That is, it is only necessary that the sensor unit 7 and the scale 2 are relatively moved.
  • an X direction (first direction) in which an X axis extends corresponds to a direction in which position detection is performed by the relative movement of the sensor unit 7 and scale 2; this direction is hereinafter referred to as "a position detection direction”.
  • a Y direction (second direction) in which a Y axis orthogonal to the X axis extends corresponds to a direction of a width of periodic patterns (later described) provided in the scale 2 so as to extend in the position detection direction; this direction is hereinafter referred to as "a scale width direction”.
  • a Z direction in which a Z axis orthogonal to the X and Y axes extends corresponds to a direction in which the sensor unit faces the scale 2, that is, the sensor unit 7 reads the periodic patterns of the scale 2; this direction is hereinafter referred to as "a scale read direction".
  • FIG. 1A shows the encoder viewed from the position detection direction
  • FIG. 1B shows the encoder viewed from the scale read direction.
  • the signal processor 51 performs an interpolation process on a sensor output signal produced by the sensor unit 7; reading and writing of a position signal (position information) from and to the memory 52; outputting of the position signal; and others.
  • the sensor unit 7 may be a transmissive optical sensor or a magnetic sensor.
  • the scale 2 is provided with periodic patterns whose each reflectance for light periodically changes in the position detection direction, in other words, each having a reflectance distribution in that direction.
  • the transmissive optical sensor the scale 2 is provided with periodic patterns whose each transmittance for light periodically changes in the position detection direction, in other words, each having a transmittance distribution in that direction.
  • the scale 2 is provided with periodic patterns each periodically changing intensity of magnetic field.
  • the sensor unit 7 as one of the above-mentioned optical sensors is unitized by housing, in one package, a light emitter 1 whose light source is an LED, a semiconductor element constituting a photo IC chip and a printed wiring board 4 on which the light emitter 1 and the semiconductor element are mounted.
  • the photo IC chip incorporates a first light receiver 3 including a plurality of light receiving elements (hereinafter referred to as "a first light receiving element array) 9, a second light receiver 12 including a plurality of light receiving elements (hereinafter referred to as "a second light receiving element array) 13 and a sensor processor performing processes such as current-voltage (I-V) conversion.
  • I-V current-voltage
  • This embodiment describes a case of using, as the first and second light receiving element arrays 9 and 13, two light receiving element arrays including a same number of light receiving elements arranged at a same pitch.
  • two light receiving element arrays including light receiving elements arranged at different pitches each optimized to periods of periodic patterns to be read by the two light receiving element arrays may be used as the first and second light receiving element arrays 9 and 13.
  • the sensor unit 7 is disposed so as to face the scale 2.
  • Light as a divergent light flux emitted from the light emitter (light source) 1 of the sensor unit 7 is projected onto the first and second scale tracks 8 and 11 of the scale 2.
  • the light projected onto the first scale track 8 is reflected by multiple periodic patterns provided in the first scale track 8 and proceeds toward the first light receiving element array 9 of the sensor unit 7 to form thereon optical images of the multiple periodic patterns of the first scale track 8.
  • the light projected onto the second scale track 11 is reflected by multiple periodic patterns provided in the second scale track 11 and proceeds toward the second light receiving element array 13 of the sensor unit 7 to form thereon optical images of the multiple periodic patterns of the second scale track 11.
  • the first and second light receivers 3 and 12 photoelectrically convert the optical images of the multiple periodic patterns (that is, read the multiple periodic patterns) respectively formed on the first and second light receiving element arrays 9 and 13, and then output sensor output signals as periodic signals respectively corresponding to the multiple periodic patterns to the signal processor 51 shown in FIG. 1A .
  • FIG. 2A shows a cross section of the scale 2 viewed from the scale width direction
  • FIG. 2B shows the scale 2 viewed from the scale read direction.
  • the scale 2 includes a base member made of plastic such as polycarbonate or of metal such as SUS. On a surface of the base member, reflective films are formed of metal such as aluminum or chrome with a predetermined period. Alternate arrangement of the high reflectance portions where the reflective films are formed and low reflectance portions where the reflective films are not formed in the position detection direction provides one periodic pattern having a period corresponding to the above predetermined period.
  • FIG. 3 shows the multiple periodic patterns provided in the respective first and second scale tracks 8 and 11 of the scale 2.
  • FIG. 3 shows an enlarged view of the periodic patterns in a region close to a boundary 31 between the first and second scale tracks 8 and 11.
  • a greater number of periodic patterns than the periodic patterns shown in FIG. 3 are provided in the scale width direction.
  • first scale track 8 two types of (that is, multiple) periodic patterns having mutually different periods (long and short periods) P1 and P2 are provided. Specifically, long period periodic patterns 112, 122 and 132 having the long period P1 and short period periodic patterns 111, 121 and 131 having the short period P2 are provided alternately and parallel in the scale width direction.
  • the second scale track 11 two types of (that is, multiple) periodic patterns having mutually different periods (long and short periods) P1' and P2' are provided. Specifically, long period periodic patterns 212, 222 and 232 having the long period P1' and short period periodic patterns 211, 221 and 231 having the short period P2' are provided alternately and parallel in the scale width direction.
  • the long periods P1 and P1' are slightly different from each other (P1 ⁇ P1'), and the short periods P2 and P2' are also slightly different from each other (P2 ⁇ P2').
  • the signal processor 51 calculates a phase difference between the sensor output signals output from the first and second light receivers 3 and 12; the sensor output signals correspond to the periodic patterns forming a pair between the first and second scale tracks 8 and 11 and having the periods P1 and P1'. Then, the signal processor 51 produces a vernier periodic signal having a period different from those of the original sensor output signals. Such processes of calculation and signal production are collectively referred to as "vernier operation". Moreover, the signal processor 51 also performs the vernier operation on the sensor output signals output from the first and second light receivers 3 and 12; the sensor output signals correspond to the periodic patterns forming a pair between the first and second scale tracks 8 and 11 and having the periods P2 and P2'.
  • the sensor output signals corresponding to the periodic patterns having the periods P1 and P1' are respectively also referred to as “a P1 period sensor output signal” and “a P1' period sensor output signal”
  • the sensor output signals corresponding to the periodic patterns having the periods P2 and P2' are respectively also referred to as “a P2 period sensor output signal” and "a P2' period sensor output signal”.
  • a long period vernier signal that is the vernier periodic signal obtained from the P1 and P1' period sensor output signals has a period (hereinafter referred to as "a long vernier period") corresponding to a lowest common multiple of P1 and P1'.
  • the periods P1 and P1' are decided such that this long vernier period becomes a desired long period.
  • a short period vernier signal that is the vernier periodic signal obtained from the P2 and P2' period sensor output signals has a period (hereinafter referred to as "a short vernier period") corresponding to a lowest common multiple of P2 and P2'.
  • the periods P2 and P2' are decided such that this short vernier period becomes a desired short period.
  • the multiple periodic patterns are arranged with respect to the boundary 31 between the first and second scale tracks 8 and 11 as follows.
  • the boundary 31 between the first and second scale tracks 8 and 11 is hereinafter referred to as "a track boundary 31".
  • a periodic pattern (hereinafter referred to as "a first periodic pattern") of the multiple periodic patterns, which is used for producing a vernier periodic signal (shortest period periodic signal) having a shortest period among the vernier periodic signals to be produced, is provided closest to the track boundary 31 among the multiple periodic patterns.
  • the first periodic pattern in this embodiment corresponds to the periodic patterns whose periods are P2 and P2' that are the shortest periods in the first and second scale tracks 8 and 11, respectively.
  • the first periodic pattern is not necessarily required to be a periodic pattern having a shortest period in each scale track.
  • an order of period length of the periodic patterns is not required to coincide with that of period length of the vernier periodic signals to be produced.
  • first and second scale tracks 8 and 11 are adjoined to each other at the track boundary 31, and the first periodic patterns, which are the periodic patterns having the shortest periods P2 and P2' in this embodiment, are adjoined to the track boundary 31.
  • the first periodic patterns (having the shortest periods P2 and P2' in this embodiment) are adjoined to each other with the track boundary 31 located therebetween.
  • the first periodic patterns included in the first and second scale tracks are not necessarily required to adjoin to the track boundary 31 or to each other, that is, these first periodic patterns may have a gap therebetween.
  • an arrangement order of the multiple (two types of) periodic patterns in the scale width direction in the first scale track 8 and that of the multiple periodic patterns in the second scale track 11 are line symmetry with respect to the track boundary 31. That is, the periods of the periodic patterns in the first scale track 8 are P2, P1, P2,... from a track boundary side (first side closer to the track boundary 31) toward an opposite-to-track boundary side (second side farther from the track boundary 31), and the periods of the periodic patterns in the second scale track 11 are P2', P1', P2',... from the track boundary side toward the opposite-to-track boundary side.
  • a periodic pattern (hereinafter referred to as "a second periodic pattern") of the multiple periodic patterns, which is used for producing a vernier periodic signal (longest period periodic signal) having a longest period among the vernier periodic signals to be produced, is provided farthest from the track boundary 31 among the multiple periodic patterns.
  • the second periodic pattern in this embodiment corresponds to the periodic patterns having the long periods P1 and P1' in the first and second scale tracks 8 and 11, respectively.
  • This embodiment describes the case where the first periodic patterns to be used for producing the vernier periodic signal having the shortest period are provided closest to the track boundary 31 among the multiple periodic patterns in both the first and second scale tracks 8 and 11. However, it is only necessary that, in at least one of the first and second scale tracks, the first periodic pattern to be used for producing the vernier periodic signal having the shortest period be provided closest to the track boundary among the multiple periodic patterns.
  • the sensor unit 7 reads, by switching its detection spatial resolution, the periodic patterns having the long periods P1 and P1' and the periodic patterns having the short periods P2 and P2', which are provided in the first and second scale tracks 8 and 11 on the scale 2.
  • the period (scale pitch) P1 is 800 ⁇ m
  • the period P1' is 816 ⁇ m
  • the period P2 is 100 ⁇ m
  • the period P2' is 102 ⁇ m
  • a total length (total stroke) of each of the periodic patterns is 40800 ⁇ m.
  • FIGS. 4 and 5 show the first light receiving element array 9 provided in the first light receiver 3 of the sensor unit 7.
  • FIG. 6 shows a configuration of the signal processor 51 of the sensor unit 7.
  • the first light receiving element array 9 32 light receiving elements are lined up in the position detection direction (X direction).
  • a length X_pd of each light receiving element in the X direction is 50 ⁇ m, and a width Y_pd thereof in the Y direction is 600 ⁇ m.
  • a total length X_total of the first light receiving element array 9 in the X direction is 1600 ⁇ m.
  • the periods P1 and P2 of the periodic patterns in the first scale track 8 are respectively set to integral multiples of the X direction length X_pd of one light receiving element.
  • the Y direction width Y_pd of each light receiving element is not necessarily required to be 600 ⁇ m.
  • the amount of received light be not changed regardless of a sensor reading position (position of an area where the sensor unit 7 reads the periodic pattern) on the first scale track 8 in the Y direction. Therefore, it is desirable that the Y direction width Y_pd be a value corresponding to 2 ⁇ n times (n represents a natural number) of a Y direction width Y0 of one group of mutually adjacent periodic patterns having the long and short periods in the first scale track 8.
  • Output from the respective light receiving elements are selectively input, through switches 41 to be switched by a switching circuit (not shown), to subsequent four first stage amplifiers (A+, B+, A- and B-).
  • the periods 800 ⁇ m and 100 ⁇ m correspond to the detection period of the first light receiver 3.
  • the first light receiver 3 is capable of reading the periodic patterns having the long and short periods P1 and P2 separately from each other depending on whether the input signal to the switching circuit has the high level or the low level.
  • the first light receiver 3 is capable of producing (acquiring) the P1 and P2 period sensor output signals separately from each other, and thus can switch the detection spatial resolution.
  • the switching of the detection spatial resolution also applies to the second light receiver 12.
  • the four first stage amplifiers 34, 35, 36 and 37 shown in FIG. 6 are I-V conversion amplifiers, and outputs thereof correspond to four phase sinusoidal outputs S(A+), S(B+), S (A-) and S (B-) .
  • the four phase sinusoidal outputs have a relation that, when one detection period is 360 degrees and the output S(A+) is a reference (0 degree), the outputs S(B+) is about +90 degrees with respect to the outputs S(A+), the outputs S(A-) is about +180 degrees with respect thereto and the output S(B-) is about +270 degrees with respect thereto.
  • This differential operation provides two sinusoidal sensor output signals S(A) and S(B) from which a DC component is removed.
  • ATAN2[Y, X] represents an arctangent function determining a quadrant of coordinates (Y, X) and converting it into a phase from 0 to 2n.
  • the relative phase difference error e1 may be stored by an initialization operation.
  • the signal processor 51 calculates, by using a maximum value and a minimum value of S(A)'+S(B)' in a predetermined range in the X direction, a value of (maximum value-minimum value)/2, and acquires the amplitude component 2 ⁇ sin(e1/2- ⁇ /4) from that calculated value.
  • the signal processor 51 calculates, by using a maximum value and a minimum value of -S(A)'+S(B)', a value of (maximum value-minimum value)/2, and acquires the amplitude component 2 ⁇ cos(e1/2- ⁇ /4) from that calculated value.
  • the signal processor 51 stores these amplitude components in the memory 52.
  • the correction of the relative phase difference can be made which includes correction of an error of an image magnification caused by a mount height displacement between the light emitter 1 and the second light receiving element array 13 and by relative tilt of the scale 2 and the sensor unit 7.
  • the signal processor 51 acquires the sensor output signals S(A) and S(B) by performing the same process.
  • the long period vernier signal Sv1 thus acquired and position of the scale 2 (hereinafter referred to as "scale position") with respect to the sensor unit 7 in the position detection direction has a relation shown in FIG. 7A .
  • the short period vernier signal Sv2 thus acquired and the scale position with respect to the sensor unit 7 in the position detection direction has a relation shown in FIG. 7B .
  • the signal processor 51 defines the long period vernier signal Sv1 as a high-level signal acquired by the expression (13) and defines the short period vernier signal Sv2 as a middle-level signal acquired by the expression (14). Then, the signal processor 51 synchronizes the high-level signal Sv1 and the middle-level signal Sv2 to acquire position information (information showing absolute position) of the scale 2.
  • the periodic patterns to be used for producing the high-level signal (long period vernier signal) Sv1 shown in FIG. 7A have the long periods P1 and P1', and are each disposed at a position of Y2 from the track boundary 31.
  • the periodic patterns to be used for producing the middle-level signal (short period vernier signal) Sv2 shown in FIG. 7B have the short periods P2 and P2'.
  • FIG. 8 is a graph showing dependence of synchronization accuracy of the high- and middle-level signals Sv1 and Sv2 and dependence of position detection accuracy (detection accuracy of the absolute position) on relative positional shift amount between the sensor unit 7 and the scale 2 in the scale width direction when the scale 2 in this embodiment is used.
  • a solid line shows the synchronization accuracy of the high- and middle-level signals Sv1 and Sv2, and a broken line shows the position detection accuracy.
  • a horizontal axis of the graph shows the relative positional shift amount ⁇ Y between the sensor unit 7 and the scale 2 in the scale width direction.
  • a first vertical axis on a left side in the graph shows the synchronization accuracy between the high- and middle-level signals Sv1 and Sv2.
  • a second vertical axis on a right side in the graph shows the position detection accuracy.
  • Y1 represents a distance between the light emitter 1 and the first and second light receivers 9 and 13 of the sensor unit 7 in the scale width direction (see FIG. 1B ).
  • a relative positional shift amount between the sensor unit 7 and the scale 2 exceeding ⁇ Y1/2 in the scale width direction gives an influence on the position detection accuracy decided by the middle-level signal Sv2.
  • a significant deterioration of the position detection accuracy such as causing of an error corresponding to at least one period of the middle-level signal Sv2 in the position detection accuracy as is the case where the high- and middle-level signals Sv1 and Sv2 cannot be synchronized can be avoided, and thereby the influence of the relative positional shift can be suppressed.
  • the periodic pattern to be used for producing the vernier periodic signal having the short (shortest) period is disposed closer to the track boundary 31 than the periodic pattern to be used for producing the vernier periodic signal having the long (longest) period.
  • This arrangement suppresses the influence of the relative positional shift between the sensor unit 7 and the scale 2 in the scale width direction on the long period vernier signal. Therefore, an allowance amount of the relative positional shift between the sensor unit 7 and the scale 2 in the scale width direction can be increased, without increasing in size of the encoder that reads the periodic patterns in the multiple scale tracks to perform the vernier position detection. As a result, even if, in the apparatus using the encoder, a backlash amount of the movable member with respect to the fixed member in the scale width direction is large to some extent, position detection of the movable member with high accuracy can be made.
  • the encoder of this embodiment is configured to produce a higher-middle-level signal and a lower-middle-level signal between the high- and middle-level signals described in Embodiment 1 to be able to accept a long stroke with higher accuracy than that in Embodiment 1.
  • This embodiment treats the middle-level signal described in Embodiment 1 as a low-level signal.
  • the configuration of the encoder of this embodiment is same as those of Embodiment 1 except that the periodic patterns are different from those in Embodiment 1.
  • description of a scale (2") is made by using reference numerals identical to those in Embodiment 1 and to which a mark (") is added, and description of other constituent elements than the scale 2" is made by using reference numerals identical to those in Embodiment 1.
  • FIG. 9 shows periodic patterns provided in a first scale track 8" and a second scale track 11" of the scale 2".
  • FIG. 9 shows an enlarged view of the periodic patterns in a region close to a boundary (track boundary) 31" between the first and second scale tracks 8" and 11".
  • a greater number of periodic patterns than the periodic patterns shown in FIG. 9 are provided in a scale width direction (Y direction).
  • multiple (four types of) periodic patterns having mutually different periods (longest, second longest, third longest and shortest) P3, P4, P5 and P6 are provided.
  • longest period periodic patterns 514, 524 and 534 having the longest period P3, second longest period periodic patterns 513, 523 and 533 having the second longest period P4 shorter than the period P3, third longest period periodic patterns 512, 522 and 532 having the third longest period P5 further shorter than the period P4 and shortest period periodic patterns 511, 521 and 531 having the shortest period P6 are provided.
  • These four types of periodic patterns are arranged parallel in ascending order of period length from an inside (a first side, that is, a track boundary side closer to the track boundary 31") toward an outside (a second side, that is, an opposite-to-track boundary side farther from the track boundary 31") in the scale width direction. Furthermore, in this embodiment, three groups of the four types of periodic patterns are provided in the first scale track 8", and these three groups of the four types of periodic patterns are cyclically arranged according to a rule of arrangement in ascending order of period length.
  • multiple (four types of) periodic patterns having mutually different periods (longest, second longest, third longest and shortest) P3', P4', P5' and P6' are provided.
  • longest period periodic patterns 614, 624 and 634 having the longest period P3', second longest period periodic patterns 613, 623 and 633 having the second longest period P4' shorter than the period P3', third longest period periodic patterns 612, 622 and 632 having the third longest period P5' further shorter than the period P4' and shortest period periodic patterns 611, 621 and 631 having the shortest period P6' are provided.
  • These four types of periodic patterns are arranged parallel, as well as in the first scale track 8", in ascending order of period length from an inside (a first side, that is, a track boundary side closer to the track boundary 31") toward an outside (a second side, that is, an opposite-to-track boundary side farther from the track boundary 31") in the scale width direction. Furthermore, in this embodiment, three groups of the four types of periodic patterns are provided in the second scale track 11", and these three groups of the four types of periodic patterns are also cyclically arranged according to the rule of arrangement in ascending order of period length.
  • the longest periods P3 and P3' are slightly different from each other (P3 ⁇ P3').
  • the second longest periods P4 and P4' and the third longest periods 5 and 5' are also respectively slightly different from each other (P4 ⁇ P4' and P5 ⁇ P5').
  • the shortest periods P6 and P6' are also slightly different from each other (P6 ⁇ P6').
  • the shortest period periodic patterns having the shortest periods P6 and P6' each correspond to "a first periodic pattern to be used for producing a vernier periodic signal having a shortest period".
  • the longest period periodic patterns having the longest periods P3 and P3' each correspond to "a second periodic pattern to be used for producing a vernier periodic signal having a longest period”.
  • the multiple periodic patterns are arranged parallel in ascending order of period length of the vernier periodic signal produced by using the periodic pattern from the inside toward the outside of the scale 2" in the scale width direction.
  • the first and second scale tracks 8" and 11" are adjoined to each other at the track boundary 31", and the first periodic patterns, which are the periodic patterns having the shortest periods P6 and P6', are adjoined to the track boundary 31".
  • the first periodic patterns (having the shortest periods P6 and P6') are adjoined to each other with the track boundary 31" located therebetween.
  • the first periodic patterns included in the first and second scale tracks are not necessarily required to adjoin to the track boundary 31" or to each other, that is, these first periodic patterns may have a gap therebetween.
  • the first periodic pattern is not necessarily required to be a periodic pattern having a shortest period in each scale track.
  • an order of period length of the periodic patterns is not required to coincide with that of period length of vernier periodic signals to be produced.
  • an arrangement order of the multiple (four types of) periodic patterns in the scale width direction in the first scale track 8" and that of the multiple periodic patterns in the second scale track 11" are line symmetry with respect to the track boundary 31". That is, the periods of the periodic patterns in the first scale track 8" are P6, P5, P4, P3, P6, ... from the track boundary 31" side toward the opposite-to-track boundary side, and the periods of the periodic patterns in the second scale track 11" are P6', P5', P4', P3', P6', ... from the track boundary side toward the opposite-to-track boundary side.
  • a second periodic pattern of the multiple (four types of) periodic patterns which is used for producing a vernier periodic signal (longest period periodic signal) having a longest period among the vernier periodic signals to be produced, is provided farthest from the track boundary 31" among the multiple periodic patterns.
  • the second periodic pattern in this embodiment corresponds to the periodic patterns having the longest periods P3 and P3' in the first and second scale tracks 8" and 11", respectively.
  • This embodiment describes the case where the first periodic patterns to be used for producing the vernier periodic signal having the shortest period is provided closest to the track boundary 31" among the multiple periodic patterns in both the first and second scale tracks 8" and 11". However, it is only necessary that, in at least one of the first and second scale tracks, the first periodic patterns to be used for producing the vernier periodic signal having the shortest period be provided closest to the track boundary among the multiple periodic patterns.
  • a vernier position detection method using the encoder of this embodiment produces, by a basically same process as that described in Embodiment 1, the following four vernier periodic signals.
  • a signal processor 51 produces, as shown in FIG. 10A , a vernier periodic signal Sv3 as a high-level signal from sensor output signals acquired by reading of the paired longest period periodic patterns having the periods P3 and P3'.
  • the signal processor 51 produces, as shown in FIG. 10B , a vernier periodic signal Sv4 as a higher-middle-level signal from sensor output signals acquired by reading of the paired second longest period periodic patterns having the periods P4 and P4'.
  • the signal processor 51 produces, as shown in FIG.
  • a vernier periodic signal Sv5 as a lower-middle-level signal from sensor output signals acquired by reading of the paired third longest period periodic patterns having the periods P5 and P5'.
  • the signal processor 51 produces, as shown in FIG. 10D , a vernier periodic signal Sv6 as a low-level signal from sensor output signals acquired by reading of the paired shortest period periodic patterns having the periods P6 and P6'. Periods of these vernier periodic signals have a relation of Sv3>Sv4>Sv5>Sv6.
  • the signal processor 51 synchronizes the high-level signal Sv3, the higher-middle-level signal Sv4, the lower-middle-level signal Sv5 and the low-level signal Sv6 to acquire position information (information showing absolute position) of the scale 2".
  • the periodic patterns to be used for producing the high-level signal (longest period vernier signal) Sv3 shown in FIG. 10A in the first and second scale tracks 8" and 11" have the longest periods P3 and P3', and are each disposed at a position of Y3 from the track boundary 31".
  • a relative positional shift amount between the sensor unit 7 and the scale 2" within a range of ⁇ (Y1/2+Y3) in the scale width direction gives no influence on the high-level signal Sv3, that is, on synchronization accuracy between the high- and higher-middle-level signals Sv3 and Sv4.
  • Y1 represents a distance between a light emitter 1 and first and second light receivers 9 and 13 of the sensor unit 7 in the scale width direction (see FIG. 1B ).
  • the periodic patterns to be used for producing the higher-middle-level signal (second longest period vernier signal) Sv4 shown in FIG. 10B in the first and second scale tracks 8" and 11" have the second longest (or third shortest) periods P4 and P4', and are each disposed at a position of Y4 ( ⁇ Y3) from the track boundary 31".
  • a relative positional shift amount between the sensor unit 7 and the scale 2" within a range of ⁇ (Y1/2+Y4) in the scale width direction gives no influence on the higher-middle-level signal Sv4, that is, on synchronization accuracy between the higher-middle- and lower-middle-level signals Sv4 and Sv5.
  • an influence corresponding to Y4 on the synchronization accuracy between the higher-middle- and lower-middle-level signals Sv4 and Sv5 can be avoided.
  • the periodic patterns to be used for producing the lower-middle-level signal (third longest period vernier signal) Sv5 shown in FIG. 10C in the first and second scale tracks 8" and 11" have the third longest (or second shortest) periods P5 and P5', and are each disposed at a position of Y5 ( ⁇ Y4) from the track boundary 31".
  • a relative positional shift amount of the sensor unit 7 and scale 2" within a range of ⁇ (Y1/2+Y5) in the scale width direction gives no influence on the lower-middle-level signal Sv5, that is, on synchronization accuracy between the lower-middle- and low-level signals Sv5 and Sv6.
  • an influence corresponding to Y5 on the synchronization accuracy between the lower-middle- and low-level signals Sv5 and Sv6 can be avoided.
  • the multiple periodic patterns are arranged from the track boundary side closer to the track boundary 31" toward the opposite-to-track boundary side farther from the track boundary 31" in ascending order of period length of the vernier periodic signals produced by using the periodic patterns.
  • This arrangement suppresses influence of the relative positional shift between the sensor unit 7 and the scale 2" in the scale width direction more effectively on the vernier periodic signal having a longer period. Therefore, an allowance amount of the relative positional shift between the sensor unit 7 and the scale 2" in the scale width direction can be increased, without increasing in size of the encoder that reads the periodic patterns in the multiple scale tracks to perform the vernier position detection.
  • a backlash amount of a movable member with respect to a fixed member in the scale width direction is large to some extent, highly accurate position detection of the movable member can be made.
  • Embodiments 1 and 2 described the configuration using the vernier periodic signal having the shortest period as the middle- or low-level signal and using the vernier periodic signal having the longest period as the high-level signal
  • a configuration may be employed which uses a vernier periodic signal having a shortest period as a lowest-level signal or uses a vernier periodic signal having a longest period as a highest-level signal.
  • FIG. 11 shows a configuration of an image pickup apparatus (or an optical apparatus) such as a digital still camera or a video camera, as an example of the apparatus equipped with the encoder described in each of Embodiments 1 and 2; the image pickup apparatus is a third embodiment (Embodiment 3) of the present invention.
  • the encoder is provided in a lens barrel of the image pickup apparatus.
  • reference numeral 21 denotes an image capturing optical system, and 22 a movable lens that is part of the image capturing optical system 21.
  • Reference numeral 7 denotes the sensor unit 7 described in Embodiments 1 and 2 and attached to a chassis (not shown) as a fixed member of the lens barrel.
  • Reference numeral 24 denotes a CPU including the signal processor 51 described in Embodiments 1 and 2.
  • Reference numeral 25 denotes an image sensor constituted by a CCD sensor or a CMOS sensor.
  • the movable lens 22 is used for autofocus or variation of magnification and is movable in the Y direction corresponding to a direction in which an optical axis extends (hereinafter referred to as "an optical axis direction").
  • Reference numeral 10 denotes a cam barrel (movable member) rotatable about the optical axis.
  • the cam barrel 10 includes a cam (not shown) in its circumferential wall portion and drives the movable lens 22 in the optical axis direction by the cam.
  • the cam barrel 10 is rotationally driven by an actuator (not shown) such as a motor.
  • Reference numeral 2 denotes the scale 2 described in Embodiment 1 or the scale 2" described in Embodiment 2.
  • the scale 2 is attached to an inner circumferential surface of the cam barrel 10 such that the position detection direction matches a rotation direction of the cam barrel 10.
  • the CPU 24 In response to movement of the movable lens 22 in the optical axis direction with rotation of the cam barrel 10, the CPU 24 performs the vernier operation described in Embodiments 1 and 2 on the sensor output signals obtained from the sensor unit 7 to detect a rotation position of the cam barrel 10. Since the rotation position of the cam barrel 10 corresponds to a position of the movable lens 22 in the optical axis direction, the CPU 24 can detect the position of the movable lens 22. The CPU 24 controls the actuator with monitoring of the detected position of the movable lens 22 to move the movable lens 22 to a target position.
  • the cam barrel 10 has mechanical backlash with respect to the chassis of the lens barrel in the optical axis direction. Therefore, the cam barrel 10 being rotated is displaced, together with the scale 2 attached thereto, with respect to the sensor unit 7 attached to the chassis in the optical axis direction corresponding to the scale width direction.
  • the encoder described in Embodiments 1 and 2 allows a certain large amount of relative positional shift between the scale 2 and the sensor unit 7. Therefore, highly accurate detection of the rotation position of the cam barrel 10 (that is, of the position of the movable lens 22 in the optical axis direction) can be made, without specially increasing dimension accuracy of parts constituting the lens barrel, such as the chassis or the cam barrel 10, and assembly accuracy of the lens barrel.
  • the encoder described in Embodiment 1 or 2 can be used not only for the above-described image pickup apparatus, but also for various apparatuses including a movable member, such as a printer (optical apparatus) performing position detection of a print head or a sheet-supplying roller, a copier (optical apparatus) performing position detection of a photoconductive drum, and an assembling apparatus including a robot arm and a carrying member to carry an assembling object and performing position detection of the robot arm or the carrier member.
  • a printer optical apparatus
  • copier optical apparatus
  • the scale (2) for a vernier encoder including a sensor (7) relatively movable with the scale in a first direction and configured to read periodic patterns provided in the scale.
  • the scale includes first and second scale tracks (8, 11) each including multiple periodic patterns (111, 112, 211, 212) having mutually different periods in the first direction and being arranged parallel in a second direction.
  • the multiple periodic patterns form, between the first and second scale tracks, multiple pairs of periodic patterns to be used for producing multiple periodic signals, each periodic signal being produced by vernier operation.
  • a first periodic pattern (111, 211) which is used for producing a shortest period periodic signal among the multiple periodic signals, is provided closest to a boundary (31) between the first and second scale tracks among the multiple periodic patterns.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optical Transform (AREA)
  • Transmission And Conversion Of Sensor Element Output (AREA)

Claims (8)

  1. Échelle (2, 2") destinée à être utilisée pour un codeur vernier comportant un capteur (7) mobile par rapport à l'échelle dans une première direction et configuré pour lire des motifs périodiques prévus dans l'échelle, l'échelle comprenant :
    une première piste d'échelle (8, 8") comportant un premier motif périodique fin (111, 511) ayant une première période dans une première direction et un premier motif périodique grossier (112, 512) ayant une période dans la première direction, qui est plus grande que la première période, où le premier motif périodique fin a la période la plus courte dans la première piste d'échelle ; et
    une deuxième piste d'échelle (11, 11") comportant un deuxième motif périodique fin (211, 611) ayant une deuxième période dans la première direction et un deuxième motif périodique grossier (212, 612) ayant une période dans la première direction, qui est plus grande que la deuxième période, où le deuxième motif périodique fin a la période la plus courte dans la deuxième piste d'échelle,
    dans laquelle la première piste d'échelle (8, 8") et la deuxième piste d'échelle (11, 11") sont agencées parallèlement dans une deuxième direction perpendiculaire à la première direction,
    caractérisée en ce que :
    la première période du premier motif périodique fin (111, 511) et la deuxième période du deuxième motif périodique fin (211, 611) sont différentes l'une de l'autre, et la période du premier motif périodique grossier (112, 512) et la période du deuxième motif périodique grossier (212, 612) sont différentes l'une de l'autre,
    le premier motif périodique fin (111, 511) et le deuxième motif périodique fin (211, 611) sont utilisés pour produire un signal périodique prédéterminé en effectuant une opération vernier sur un signal obtenu par lecture du premier motif périodique fin par le capteur et sur un signal obtenu par lecture du deuxième motif périodique fin par le capteur,
    le premier motif périodique grossier (112, 512) et le deuxième motif périodique grossier (212, 612) sont utilisés pour produire un signal périodique, dont la période est plus grande que celle du signal périodique prédéterminé, en effectuant une opération vernier sur un signal obtenu par lecture du premier motif périodique grossier par le capteur et sur un signal obtenu par lecture du deuxième motif périodique grossier par le capteur, et
    le premier motif périodique fin (111, 511) inclus dans la première piste d'échelle (8, 8") est agencé le plus proche de la deuxième piste d'échelle (11, 11"), et le deuxième motif périodique fin (211, 611) inclus dans la deuxième piste d'échelle (11, 11") est agencé le plus proche de la première piste d'échelle (8, 8").
  2. Échelle selon la revendication 1, dans laquelle les première et deuxième pistes d'échelle sont contigües l'une à l'autre, et
    dans laquelle le premier motif périodique fin inclus dans la première piste d'échelle est contigu à une limite (31, 31") entre les première et deuxième pistes d'échelle.
  3. Échelle selon la revendication 1 ou 2, dans laquelle le premier motif périodique fin inclus dans la première piste d'échelle et le deuxième motif périodique fin inclus dans la deuxième piste d'échelle sont contigus l'un à l'autre avec une limite (31, 31") à travers les première et deuxième pistes d'échelle.
  4. Échelle selon l'une quelconque des revendications 1 à 3, dans laquelle, dans la première piste d'échelle, le premier motif périodique grossier est prévu le plus éloigné d'une limite (31, 31") entre les première et deuxième pistes d'échelle, et, dans la deuxième piste d'échelle, le deuxième motif périodique grossier est prévu le plus éloigné de la limite (31, 31").
  5. Échelle selon l'une quelconque des revendications 1 à 4, dans laquelle, dans la première piste d'échelle, le premier motif périodique fin et le premier motif périodique grossier sont agencés parallèlement d'un côté plus proche d'une limite (31, 31") entre les première et deuxième pistes d'échelle vers un côté plus éloigné de la limite (31, 31") dans un ordre croissant de longueur de période de signaux périodiques produits en utilisant les motifs périodiques, et, dans la deuxième piste d'échelle, le deuxième motif périodique fin et le deuxième motif périodique grossier sont agencés parallèlement d'un côté plus proche de la limite (31, 31") vers un côté plus éloigné de la limite (31, 31") dans un ordre croissant de longueur périodique de signaux périodiques en utilisant les motifs périodiques.
  6. Codeur vernier, caractérisé en ce qu'il comprend :
    une échelle (2) selon l'une quelconque des revendications 1 à 5 ; et
    un capteur (7) mobile par rapport à l'échelle dans la première direction et configuré pour lire des motifs périodiques (111, 112, 211, 212) prévus dans l'échelle.
  7. Codeur vernier selon la revendication 6, dans lequel le capteur comprend :
    un émetteur de lumière (1) ; et
    un récepteur de lumière (9, 13) configuré pour recevoir la lumière émise par l'émetteur de lumière et transmise à travers ou réfléchie par le motif périodique prévu dans l'échelle.
  8. Appareil caractérisé en ce qu'il comprend :
    un codeur vernier selon la revendication 6 ou 7 ; et
    un élément mobile (10) auquel l'un parmi l'échelle et le capteur est fixé et qui est mobile par rapport à un élément fixe auquel l'autre parmi l'échelle et le capteur est fixé.
EP13166364.3A 2012-05-07 2013-05-03 Échelle, codeur vernier et appareil l'utilisant Active EP2662668B1 (fr)

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JP6313571B2 (ja) * 2013-11-12 2018-04-18 キヤノン株式会社 位置検出装置及びそれを有するレンズ装置及び撮影装置
JP5877212B2 (ja) 2014-01-10 2016-03-02 キヤノンプレシジョン株式会社 エンコーダ、エンコーダを用いた装置およびエンコーダ演算プログラム
JP6400345B2 (ja) * 2014-06-17 2018-10-03 株式会社ミツトヨ 光学式エンコーダ及び光学式エンコーダにおける原点信号生成方法
JP6544945B2 (ja) * 2015-03-03 2019-07-17 キヤノン株式会社 位置検出装置、これを用いた装置及び位置検出方法
US10113888B2 (en) 2015-03-03 2018-10-30 Canon Kabushiki Kaisha Position detection apparatus, apparatus including the same and position detection method
JP6544946B2 (ja) * 2015-03-03 2019-07-17 キヤノン株式会社 位置検出装置、これを用いた装置及び位置検出方法
DE102015121812B4 (de) * 2015-12-15 2017-11-02 Bogen Electronic Gmbh Gegenstand, Verfahren zum Herstellen des Gegenstands und Verfahren zum Bestimmen einer Position des Gegenstands
EP3611476A4 (fr) * 2017-04-13 2020-07-29 Sony Corporation Dispositif de détection de position et procédé de détection de position
JP7046596B2 (ja) * 2017-12-25 2022-04-04 キヤノン株式会社 レンズ鏡筒及び光学機器
JP7118809B2 (ja) 2018-08-27 2022-08-16 キヤノン株式会社 位置検出装置およびこれを備えた装置、位置検出方法およびコンピュータプログラム
JP2020148551A (ja) * 2019-03-12 2020-09-17 キヤノン株式会社 光検出装置および光学エンコーダ装置

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3768094A (en) * 1971-12-10 1973-10-23 C Henrich Digital encoder and position reference
DE19944005A1 (de) * 1999-09-14 2001-03-15 Kostal Leopold Gmbh & Co Kg Optoelektronischer Drehwinkelsensor
DE112009001319B4 (de) * 2008-06-05 2013-06-06 Mitsubishi Electric Corp. Optischer Encoder
JP5566061B2 (ja) 2009-07-31 2014-08-06 オリンパス株式会社 光学式変位検出装置
JP5479255B2 (ja) * 2010-07-20 2014-04-23 キヤノン株式会社 光学式エンコーダ

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JP2013234861A (ja) 2013-11-21
US9347802B2 (en) 2016-05-24

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